Heretofore, injections containing fentanyl or a salt thereof as a drug have been used as analgesic agents for cancer pain and the like. In recent years, in addition to the injections, patches containing fentanyl or a salt thereof have been developed, and have been studied on matters such as improvements in transdermal absorbability and temporal stability of the drug.
For example, Japanese Unexamined Patent Application Publication No. Hei 10-45570 (PLT 1) discloses a fentanyl-containing transdermal administration tape preparation containing fentanyl or a salt thereof, an adhesive, and sodium acetate, and states that antioxidants which may be added to the preparation as optional ingredients antioxidant include tocopherol and ester derivatives thereof, ascorbic acid, stearic acid ester, nordihydroguaiaretic acid, dibutylhydroxytoluene (BHT), butylhydroxyanisole (BHA), and the like.
In addition, Japanese Unexamined Patent Application Publication No. 2010-30909 (PLT 2) discloses a transdermal absorption patch in which an adhesive layer contains an effective amount of fentanyl or a salt thereof, and a sufficient amount of a hindered phenolic antioxidant to inhibit precipitation of the fentanyl or the salt thereof, and mentions, as the hindered phenolic antioxidant, 2,6-di-t-butyl-p-cresol, pentaerythrityl tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], and the like.
Furthermore, Japanese Unexamined Patent Application Publication No. 2010-6761 (PLT 3) discloses a transdermal absorption patch containing fentanyl or a salt thereof and containing a rosin resin treated with an antioxidant, and states that one kind or a combination of two or more kinds among tocopherol and ester derivatives thereof, ascorbic acid, ascorbic acid esters, nordihydroguaiaretic acid, and phenolic antioxidants is used as the antioxidant.
In addition, Japanese Unexamined Patent Application Publication No. 2010-6762 (PLT 4) discloses a pharmaceutical composition containing fentanyl or a salt thereof and containing 0.01 to 0.5% by mass of ascorbic acid or an ester thereof, and states that the pharmaceutical composition may further contain a phenolic antioxidant, tocopherol or an ester derivative thereof, nordihydroguaiaretic acid, butylhydroxyanisole, or the like as an antioxidant other than the ascorbic acid or the ester thereof.